findElementById

Returns the single element that contains an Id with value
uri and namespace. The Id can be either a wsu:Id or an Id
with no namespace. This is a replacement for a XPath Id lookup with the given namespace.
It's somewhat faster than XPath, and we do not deal with prefixes, just with the real
namespace URI
If checkMultipleElements is true and there are multiple elements, we LOG.a
warning and return null as this can be used to get around the signature checking.

Parameters:

startNode - Where to start the search

value - Value of the Id attribute

checkMultipleElements - If true then go through the entire tree and return
null if there are multiple elements with the same Id

Returns:

The found element if there was exactly one match, or
null otherwise

setNamespace

Set a namespace/prefix on an element if it is not set already. First off, it
searches for the element for the prefix associated with the specified
namespace. If the prefix isn't null, then this is returned. Otherwise, it
creates a new attribute using the namespace/prefix passed as parameters.